<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">

  <title>圣诞树</title>

  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/5.0.0/normalize.min.css">

  <style>
    * {
      box-sizing: border-box;
    }


    body {
      margin: 0;
      height: 100vh;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
      background: #161616;
      color: #c5a880;
      font-family: sans-serif;
    }


    label {
      display: inline-block;
      background-color: #161616;
      padding: 16px;
      border-radius: 0.3rem;
      cursor: pointer;
      margin-top: 1rem;
      width: 300px;
      border-radius: 10px;
      border: 1px solid #c5a880;
      text-align: center;
    }


    ul {
      list-style-type: none;
      padding: 0;
      margin: 0;
    }


    .btn {
      background-color: #161616;
      border-radius: 10px;
      color: #c5a880;
      border: 1px solid #c5a880;
      padding: 16px;
      width: 300px;
      margin-bottom: 16px;
      line-height: 1.5;
      cursor: pointer;
    }

    .separator {
      font-weight: bold;
      text-align: center;
      width: 300px;
      margin: 16px 0px;
      color: #a07676;
    }


    .title {
      color: #a07676;
      font-weight: bold;
      font-size: 1.25rem;
      margin-bottom: 16px;
    }


    .text-loading {
      font-size: 2rem;
    }
  </style>

  <script>
    window.console = window.console || function (t) { };
  </script>



  <script>
    if (document.location.search.match(/type=embed/gi)) {
      window.parent.postMessage("resize", "*");
    }
  </script>


</head>

<body translate="no">
<script src="https://cdn.jsdelivr.net/npm/three@0.115.0/build/three.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/three@0.115.0/examples/js/postprocessing/EffectComposer.js"></script>
<script src="https://cdn.jsdelivr.net/npm/three@0.115.0/examples/js/postprocessing/RenderPass.js"></script>
<script src="https://cdn.jsdelivr.net/npm/three@0.115.0/examples/js/postprocessing/ShaderPass.js"></script>
<script src="https://cdn.jsdelivr.net/npm/three@0.115.0/examples/js/shaders/CopyShader.js"></script>
<script src="https://cdn.jsdelivr.net/npm/three@0.115.0/examples/js/shaders/LuminosityHighPassShader.js"></script>
<script src="https://cdn.jsdelivr.net/npm/three@0.115.0/examples/js/postprocessing/UnrealBloomPass.js"></script>

<div id="overlay">
  <ul>
    <li class="title">请选择音乐</li>
    <li>
      <button class="btn" id="btnA" type="button">
        Snowflakes Falling Down by Simon Panrucker
      </button>
    </li>
    <li><button class="btn" id="btnB" type="button">This Christmas by Dott</button></li>
    <li><button class="btn" id="btnC" type="button">No room at the inn by TRG Banks</button></li>
    <li><button class="btn" id="btnD" type="button">Jingle Bell Swing by Mark Smeby</button></li>
    <li class="separator">或者</li>
    <li>
      <input type="file" id="upload" hidden />
      <label for="upload">Upload File</label>
    </li>
  </ul>
</div>

<script id="rendered-js">
  const { PI, sin, cos } = Math;
  const TAU = 2 * PI;

  const map = (value, sMin, sMax, dMin, dMax) => {
    return dMin + (value - sMin) / (sMax - sMin) * (dMax - dMin);
  };

  const range = (n, m = 0) =>
          Array(n).
          fill(m).
          map((i, j) => i + j);

  const rand = (max, min = 0) => min + Math.random() * (max - min);
  const randInt = (max, min = 0) => Math.floor(min + Math.random() * (max - min));
  const randChoise = arr => arr[randInt(arr.length)];
  const polar = (ang, r = 1) => [r * cos(ang), r * sin(ang)];

  let scene, camera, renderer, analyser;
  let step = 0;
  const uniforms = {
    time: { type: "f", value: 0.0 },
    step: { type: "f", value: 0.0 }
  };

  const params = {
    exposure: 1,
    bloomStrength: 0.9,
    bloomThreshold: 0,
    bloomRadius: 0.5
  };

  let composer;

  const fftSize = 2048;
  const totalPoints = 4000;

  const listener = new THREE.AudioListener();

  const audio = new THREE.Audio(listener);

  document.querySelector("input").addEventListener("change", uploadAudio, false);

  const buttons = document.querySelectorAll(".btn");
  buttons.forEach((button, index) =>
          button.addEventListener("click", () => loadAudio(index)));


  function init() {
    const overlay = document.getElementById("overlay");
    overlay.remove();

    scene = new THREE.Scene();
    renderer = new THREE.WebGLRenderer({ antialias: true });
    renderer.setPixelRatio(window.devicePixelRatio);
    renderer.setSize(window.innerWidth, window.innerHeight);
    document.body.appendChild(renderer.domElement);

    camera = new THREE.PerspectiveCamera(
            60,
            window.innerWidth / window.innerHeight,
            1,
            1000);

    camera.position.set(-0.09397456774197047, -2.5597086635726947, 24.420789670889008);
    camera.rotation.set(0.10443543723052419, -0.003827152981119352, 0.0004011488708739715);

    const format = renderer.capabilities.isWebGL2 ?
            THREE.RedFormat :
            THREE.LuminanceFormat;

    uniforms.tAudioData = {
      value: new THREE.DataTexture(analyser.data, fftSize / 2, 1, format)
    };


    addPlane(scene, uniforms, 3000);
    addSnow(scene, uniforms);

    range(10).map(i => {
      addTree(scene, uniforms, totalPoints, [20, 0, -20 * i]);
      addTree(scene, uniforms, totalPoints, [-20, 0, -20 * i]);
    });

    const renderScene = new THREE.RenderPass(scene, camera);

    const bloomPass = new THREE.UnrealBloomPass(
            new THREE.Vector2(window.innerWidth, window.innerHeight),
            1.5,
            0.4,
            0.85);

    bloomPass.threshold = params.bloomThreshold;
    bloomPass.strength = params.bloomStrength;
    bloomPass.radius = params.bloomRadius;

    composer = new THREE.EffectComposer(renderer);
    composer.addPass(renderScene);
    composer.addPass(bloomPass);

    addListners(camera, renderer, composer);
    animate();
  }

  function animate(time) {
    analyser.getFrequencyData();
    uniforms.tAudioData.value.needsUpdate = true;
    step = (step + 1) % 1000;
    uniforms.time.value = time;
    uniforms.step.value = step;
    composer.render();
    requestAnimationFrame(animate);
  }

  function loadAudio(i) {
    document.getElementById("overlay").innerHTML =
            '<div class="text-loading">正在下载音乐，请稍等...</div>';
    const files = [
      "https://files.freemusicarchive.org/storage-freemusicarchive-org/music/no_curator/Simon_Panrucker/Happy_Christmas_You_Guys/Simon_Panrucker_-_01_-_Snowflakes_Falling_Down.mp3",
      "https://files.freemusicarchive.org/storage-freemusicarchive-org/music/no_curator/Dott/This_Christmas/Dott_-_01_-_This_Christmas.mp3",
      "https://files.freemusicarchive.org/storage-freemusicarchive-org/music/ccCommunity/TRG_Banks/TRG_Banks_Christmas_Album/TRG_Banks_-_12_-_No_room_at_the_inn.mp3",
      "https://files.freemusicarchive.org/storage-freemusicarchive-org/music/ccCommunity/Mark_Smeby/En_attendant_Nol/Mark_Smeby_-_07_-_Jingle_Bell_Swing.mp3"];

    const file = files[i];

    const loader = new THREE.AudioLoader();
    loader.load(file, function (buffer) {
      audio.setBuffer(buffer);
      audio.play();
      analyser = new THREE.AudioAnalyser(audio, fftSize);
      init();
    });




  }


  function uploadAudio(event) {
    document.getElementById("overlay").innerHTML =
            '<div class="text-loading">请稍等...</div>';
    const files = event.target.files;
    const reader = new FileReader();

    reader.onload = function (file) {
      var arrayBuffer = file.target.result;

      listener.context.decodeAudioData(arrayBuffer, function (audioBuffer) {
        audio.setBuffer(audioBuffer);
        audio.play();
        analyser = new THREE.AudioAnalyser(audio, fftSize);
        init();
      });
    };

    reader.readAsArrayBuffer(files[0]);
  }

  function addTree(scene, uniforms, totalPoints, treePosition) {
    const vertexShader = `
      attribute float mIndex;
      varying vec3 vColor;
      varying float opacity;
      uniform sampler2D tAudioData;
      float norm(float value, float min, float max ){
       return (value - min) / (max - min);
      }
      float lerp(float norm, float min, float max){
       return (max - min) * norm + min;
      }
      float map(float value, float sourceMin, float sourceMax, float destMin, float destMax){
       return lerp(norm(value, sourceMin, sourceMax), destMin, destMax);
      }
      void main() {
       vColor = color;
       vec3 p = position;
       vec4 mvPosition = modelViewMatrix * vec4( p, 1.0 );
       float amplitude = texture2D( tAudioData, vec2( mIndex, 0.1 ) ).r;
       float amplitudeClamped = clamp(amplitude-0.4,0.0, 0.6 );
       float sizeMapped = map(amplitudeClamped, 0.0, 0.6, 1.0, 20.0);
       opacity = map(mvPosition.z , -200.0, 15.0, 0.0, 1.0);
       gl_PointSize = sizeMapped * ( 100.0 / -mvPosition.z );
       gl_Position = projectionMatrix * mvPosition;
      }
      `;
    const fragmentShader = `
      varying vec3 vColor;
      varying float opacity;
      uniform sampler2D pointTexture;
      void main() {
       gl_FragColor = vec4( vColor, opacity );
       gl_FragColor = gl_FragColor * texture2D( pointTexture, gl_PointCoord );
      }
      `;
    const shaderMaterial = new THREE.ShaderMaterial({
      uniforms: {
        ...uniforms,
        pointTexture: {
          value: new THREE.TextureLoader().load(`https://assets.codepen.io/3685267/spark1.png`)
        }
      },


      vertexShader,
      fragmentShader,
      blending: THREE.AdditiveBlending,
      depthTest: false,
      transparent: true,
      vertexColors: true
    });


    const geometry = new THREE.BufferGeometry();
    const positions = [];
    const colors = [];
    const sizes = [];
    const phases = [];
    const mIndexs = [];

    const color = new THREE.Color();

    for (let i = 0; i < totalPoints; i++) {
      const t = Math.random();
      const y = map(t, 0, 1, -8, 10);
      const ang = map(t, 0, 1, 0, 6 * TAU) + TAU / 2 * (i % 2);
      const [z, x] = polar(ang, map(t, 0, 1, 5, 0));

      const modifier = map(t, 0, 1, 1, 0);
      positions.push(x + rand(-0.3 * modifier, 0.3 * modifier));
      positions.push(y + rand(-0.3 * modifier, 0.3 * modifier));
      positions.push(z + rand(-0.3 * modifier, 0.3 * modifier));

      color.setHSL(map(i, 0, totalPoints, 1.0, 0.0), 1.0, 0.5);

      colors.push(color.r, color.g, color.b);
      phases.push(rand(1000));
      sizes.push(1);
      const mIndex = map(i, 0, totalPoints, 1.0, 0.0);
      mIndexs.push(mIndex);
    }

    geometry.setAttribute(
            "position",
            new THREE.Float32BufferAttribute(positions, 3).setUsage(
                    THREE.DynamicDrawUsage));


    geometry.setAttribute("color", new THREE.Float32BufferAttribute(colors, 3));
    geometry.setAttribute("size", new THREE.Float32BufferAttribute(sizes, 1));
    geometry.setAttribute("phase", new THREE.Float32BufferAttribute(phases, 1));
    geometry.setAttribute("mIndex", new THREE.Float32BufferAttribute(mIndexs, 1));

    const tree = new THREE.Points(geometry, shaderMaterial);

    const [px, py, pz] = treePosition;

    tree.position.x = px;
    tree.position.y = py;
    tree.position.z = pz;

    scene.add(tree);
  }

  function addSnow(scene, uniforms) {
    const vertexShader = `
      attribute float size;
      attribute float phase;
      attribute float phaseSecondary;
      varying vec3 vColor;
      varying float opacity;
      uniform float time;
      uniform float step;
      float norm(float value, float min, float max ){
       return (value - min) / (max - min);
      }
      float lerp(float norm, float min, float max){
       return (max - min) * norm + min;
      }
      float map(float value, float sourceMin, float sourceMax, float destMin, float destMax){
       return lerp(norm(value, sourceMin, sourceMax), destMin, destMax);
      }
      void main() {
       float t = time* 0.0006;
       vColor = color;
       vec3 p = position;
       p.y = map(mod(phase+step, 1000.0), 0.0, 1000.0, 25.0, -8.0);
       p.x += sin(t+phase);
       p.z += sin(t+phaseSecondary);
       opacity = map(p.z, -150.0, 15.0, 0.0, 1.0);
       vec4 mvPosition = modelViewMatrix * vec4( p, 1.0 );
       gl_PointSize = size * ( 100.0 / -mvPosition.z );
       gl_Position = projectionMatrix * mvPosition;
      }
      `;

    const fragmentShader = `
      uniform sampler2D pointTexture;
      varying vec3 vColor;
      varying float opacity;
      void main() {
       gl_FragColor = vec4( vColor, opacity );
       gl_FragColor = gl_FragColor * texture2D( pointTexture, gl_PointCoord );
      }
      `;
    function createSnowSet(sprite) {
      const totalPoints = 300;
      const shaderMaterial = new THREE.ShaderMaterial({
        uniforms: {
          ...uniforms,
          pointTexture: {
            value: new THREE.TextureLoader().load(sprite)
          }
        },


        vertexShader,
        fragmentShader,
        blending: THREE.AdditiveBlending,
        depthTest: false,
        transparent: true,
        vertexColors: true
      });


      const geometry = new THREE.BufferGeometry();
      const positions = [];
      const colors = [];
      const sizes = [];
      const phases = [];
      const phaseSecondaries = [];

      const color = new THREE.Color();

      for (let i = 0; i < totalPoints; i++) {
        const [x, y, z] = [rand(25, -25), 0, rand(15, -150)];
        positions.push(x);
        positions.push(y);
        positions.push(z);

        color.set(randChoise(["#f1d4d4", "#f1f6f9", "#eeeeee", "#f1f1e8"]));

        colors.push(color.r, color.g, color.b);
        phases.push(rand(1000));
        phaseSecondaries.push(rand(1000));
        sizes.push(rand(4, 2));
      }

      geometry.setAttribute(
              "position",
              new THREE.Float32BufferAttribute(positions, 3));

      geometry.setAttribute("color", new THREE.Float32BufferAttribute(colors, 3));
      geometry.setAttribute("size", new THREE.Float32BufferAttribute(sizes, 1));
      geometry.setAttribute("phase", new THREE.Float32BufferAttribute(phases, 1));
      geometry.setAttribute(
              "phaseSecondary",
              new THREE.Float32BufferAttribute(phaseSecondaries, 1));


      const mesh = new THREE.Points(geometry, shaderMaterial);

      scene.add(mesh);
    }
    const sprites = [
      "https://assets.codepen.io/3685267/snowflake1.png",
      "https://assets.codepen.io/3685267/snowflake2.png",
      "https://assets.codepen.io/3685267/snowflake3.png",
      "https://assets.codepen.io/3685267/snowflake4.png",
      "https://assets.codepen.io/3685267/snowflake5.png"];

    sprites.forEach(sprite => {
      createSnowSet(sprite);
    });
  }

  function addPlane(scene, uniforms, totalPoints) {
    const vertexShader = `
      attribute float size;
      attribute vec3 customColor;
      varying vec3 vColor;
      void main() {
       vColor = customColor;
       vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
       gl_PointSize = size * ( 300.0 / -mvPosition.z );
       gl_Position = projectionMatrix * mvPosition;
      }
      `;
    const fragmentShader = `
      uniform vec3 color;
      uniform sampler2D pointTexture;
      varying vec3 vColor;
      void main() {
       gl_FragColor = vec4( vColor, 1.0 );
       gl_FragColor = gl_FragColor * texture2D( pointTexture, gl_PointCoord );
      }
      `;
    const shaderMaterial = new THREE.ShaderMaterial({
      uniforms: {
        ...uniforms,
        pointTexture: {
          value: new THREE.TextureLoader().load(`https://assets.codepen.io/3685267/spark1.png`)
        }
      },


      vertexShader,
      fragmentShader,
      blending: THREE.AdditiveBlending,
      depthTest: false,
      transparent: true,
      vertexColors: true
    });


    const geometry = new THREE.BufferGeometry();
    const positions = [];
    const colors = [];
    const sizes = [];

    const color = new THREE.Color();

    for (let i = 0; i < totalPoints; i++) {
      const [x, y, z] = [rand(-25, 25), 0, rand(-150, 15)];
      positions.push(x);
      positions.push(y);
      positions.push(z);

      color.set(randChoise(["#93abd3", "#f2f4c0", "#9ddfd3"]));

      colors.push(color.r, color.g, color.b);
      sizes.push(1);
    }

    geometry.setAttribute(
            "position",
            new THREE.Float32BufferAttribute(positions, 3).setUsage(
                    THREE.DynamicDrawUsage));


    geometry.setAttribute(
            "customColor",
            new THREE.Float32BufferAttribute(colors, 3));

    geometry.setAttribute("size", new THREE.Float32BufferAttribute(sizes, 1));

    const plane = new THREE.Points(geometry, shaderMaterial);

    plane.position.y = -8;
    scene.add(plane);
  }

  function addListners(camera, renderer, composer) {
    document.addEventListener("keydown", e => {
      const { x, y, z } = camera.position;
      console.log(`camera.position.set(${x},${y},${z})`);
      const { x: a, y: b, z: c } = camera.rotation;
      console.log(`camera.rotation.set(${a},${b},${c})`);
    });

    window.addEventListener(
            "resize",
            () => {
              const width = window.innerWidth;
              const height = window.innerHeight;

              camera.aspect = width / height;
              camera.updateProjectionMatrix();

              renderer.setSize(width, height);
              composer.setSize(width, height);
            },
            false);

  }
</script>

</body>

</html>
